Vacuum cleaner exhaust filter with ion generation stage

• US 6,171,375 B1
• Filed: 03/29/1999
• Issued: 01/09/2001
• Est. Priority Date: 12/16/1998
• Status: Expired due to Term

• Current Assignee: Electrolux PLC (AB Electrolux)
• Original Assignee: Electrolux PLC (AB Electrolux)
• Inventors: Howie, Mark S.
• Primary Examiner(s): Chiesa, Richard L.
• Application Number:
  US09/277,727
• Time in Patent Office: 652 Days
• Field of Search: 96/17, 96/57, 96/58, 96/63, 96/66, 96/96, 554/86, 55D/IG.3, 55D/IG.39, 153/47, 153/52
• US Class Current: 96/17
• CPC Class Codes: A47L 9/122 flat
• CPC Class Codes: B01D 2267/40 Different types of filters
• CPC Class Codes: B01D 2279/55 for cleaning appliances, e.g. suction cleaners
• CPC Class Codes: B01D 46/0036 by adsorption or absorption
• CPC Class Codes: B01D 46/02 Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
• CPC Class Codes: B01D 46/50 Means for discharging electrostatic potential
• CPC Class Codes: B01D 46/521 using folded, pleated material
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B03C 3/30 in which electrostatic charge is generated by passage of the gases, i.e. tribo-electricity
• CPC Class Codes: Y10S 55/03 Vacuum cleaner

Abstract

A vacuum cleaner exhaust filter assembly includes a main HEPA exhaust filter, and an ion generation stage to add ions to the air. The ion generation stage preferably is a polypropylene mesh which generates ions through static electric interaction with the moving air as the result of friction. The exhaust filter assembly preferably also includes a pre-filter impregnated with carbon, preferably in the form of activated charcoal, to absorb odors from the exhaust air. The filter components, arranged in the preferred order, are the carbon pre-filter, the main HEPA exhaust filter, and the ion generation mesh.

Claims

1. A filter assembly for placement in a vacuum cleaner exhaust flow path, exhaust flow in said exhaust flow path having a flow direction, said filter assembly comprising:

a pre-filter element;

a filter element downstream of said pre-filter element along said flow direction;

a plastic mesh downstream of said filter element along said flow direction for ionizing said exhaust flow, thereby introducing ions into air exiting said exhaust flow path; and

a housing enclosing said pre-filter element, said filter element and said plastic mesh, said housing comprising a first housing portion, and a second housing portion having an array of holes serving as an exhaust grill.

2. The filter assembly of claim 1 wherein said plastic mesh is a polypropylene mesh.

3. The filter assembly of claim 2 wherein said polypropylene mesh is coarsely woven.

4. The filter assembly of claim 3 wherein said polypropylene mesh has about 32×

30 strands per inch (about 13×

12 strands per centimeter).

5. The filter assembly of claim 1 wherein said filter element is a HEPA filter.

6. The filter assembly of claim 1 wherein said pre-filter element comprises a carbon filter.

7. The filter assembly of claim 6 wherein said carbon filter comprises an activated charcoal filter.

8. The filter assembly of claim 1 wherein said plastic mesh ionizes said exhaust flow passively.

9. A vacuum cleaner comprising:

a body, said body having a suction opening therein for the entry of dirt-laden air and an exhaust opening therein for the exit of said dirt-laden air after dirt has been substantially removed therefrom;

an air-flow path between said suction opening and said exhaust opening;

a motor/fan unit for creating air flow in a flow direction in said air-flow path, said air flow drawing said dirt-laden air in through said suction opening;

a dirt collection chamber within said body, said air-flow path passing through said dirt collection chamber;

a primary filter in said dirt collection chamber for removing dirt from said dirt-laden air; and

an exhaust filter between said primary filter and said exhaust opening for removing dirt remaining in said dirt-laden air downstream of said primary filter along said air-flow path, said exhaust filter comprising;

a pre-filter element,

a filter element downstream of said prefilter element along said air-flow path,

a plastic mesh downstream of said filter element along said air-flow path for ionizing said air flow, thereby introducing ions into air exiting said air-flow path, and

a housing enclosing said pre-filter element, said filter element and said plastic mesh.

10. The vacuum cleaner of claim 9 wherein said plastic mesh is a polypropylene mesh.

11. The vacuum cleaner of claim 10 wherein said polypropylene mesh is coarsely woven.

12. The vacuum cleaner of claim 11 wherein said polypropylene mesh has about 32×

30 strands per inch (about 13×

12 strands per centimeter).

13. The vacuum cleaner of claim 9 wherein said filter element is a HEPA filter.

14. The vacuum cleaner of claim 9 wherein said pre-filter element comprises a carbon filter.

15. The vacuum cleaner of claim 14 wherein said carbon filter comprises an activated charcoal filter.

16. The vacuum cleaner of claim 9 wherein said plastic mesh ionizes said air flow passively.